WASHINGTON (AP) -- Vice President Dick Cheney's office acknowledged on Thursday that he was mistaken when he asserted that China, at Cuba's behest, is drilling for oil in waters 60 miles from the Florida coast. In a speech to the U.S. Chamber of Commerce, Cheney said on Wednesday that waters in the eastern Gulf of Mexico, long off limits to oil companies, should be opened to drilling because China is already there pumping oil. ''Oil is being drilled right now 60 miles off the coast of Florida,'' the vice president said. ''We're not doing it, the Chinese are, in cooperation...